<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

/**
 * Description of DESCoder
 *
 * @author tony
 */
class DESCoder {
    var $key;  
    
    function __construct($p) {        
        $this->key = $p['key'];         
    }
    
    function encrypt($input)   
    {         
       $size = mcrypt_get_block_size('des','ecb');  
       $input = $this->pkcs5_pad($input, $size);  
       $key = $this->key;  
       $td = mcrypt_module_open('des', '', 'ecb', '');  
       $iv = @mcrypt_create_iv (mcrypt_enc_get_iv_size($td), MCRYPT_RAND);  
       @mcrypt_generic_init($td, $key, $iv);  
       $data = mcrypt_generic($td, $input);  
       mcrypt_generic_deinit($td);  
       mcrypt_module_close($td);  
       $data = base64_encode($data);  
       return $data;  
    }    
    
    function decrypt($encrypted)  
    {         
       $encrypted = base64_decode($encrypted);  
       $key =$this->key;  
       $td = mcrypt_module_open('des','','ecb','');   
       //使用MCRYPT_DES算法,cbc模式  
       $iv = @mcrypt_create_iv(mcrypt_enc_get_iv_size($td), MCRYPT_RAND);  
       $ks = mcrypt_enc_get_key_size($td);  
       @mcrypt_generic_init($td, $key, $iv);  
       //初始处理                 
       $decrypted = mdecrypt_generic($td, $encrypted);  
       //解密  
       mcrypt_generic_deinit($td);  
       //结束               
       mcrypt_module_close($td);  
       $y=$this->pkcs5_unpad($decrypted);  
       return $y;     
    }    
    
    function pkcs5_pad ($text, $blocksize)   
    {         
       $pad = $blocksize - (strlen($text) % $blocksize);  
       return $text . str_repeat(chr($pad), $pad);  
    }    
    
    function pkcs5_unpad($text)   
    {         
       $pad = ord($text{strlen($text)-1});  
       if ($pad > strlen($text))  
       {  
           return false;  
       }  
       if (strspn($text, chr($pad), strlen($text) - $pad) != $pad)  
       {  
          return false;  
       }  
       return substr($text, 0, -1 * $pad);  
    }  
}

?>
